Chair back upright



FIG. 1 is a perspective view of a chair back upright, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof,

FIG. 8 is a rear perspective view thereof; and,

FIG. 9 is a perspective view of the chair back upright embodying our design.

The broken lines showing an outline of a chair and certain features of the chair are for illustrative purposes only, and form no part of the claimed design. 

CLAIM The ornamental design for a chair back upright, as shown and described. 